From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The testing and development of Lucas Wind Tone Horns, Type WT.23, compared to the standard WT.13.
| Identifier | ExFiles\Box 166\9\ img192 | |
| Date | 23th February 1939 | |
| 6066 To By/RD. c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/RC.{R. Childs}10/JH.23.2.39. Lucas Wind Tone Horns. Type WT.23. The heavy current taken by our standard WT.13 type horns, is a point that we have frequently raised with the Makers in the past. This current is about 20 to 22 amperes and apart from the load on the battery it was thought that it might be the cause of horns failing through getting out of adjustment as the result of excessive wear of the contact points. It was urged that an attempt should be made to reduce the current required, and eventually in June 1937 a pair of horns were submitted for trial with this object. These horns were designated type WT.23 and externally were identical with our standard. The operating element however was much simpler and was found to take about 5 amperes, roughly half the current taken by the standard horns. Unfortunately the road test report was that they were not penetrating enough for high-speed travelling. Ultimately they were removed from the car and returned to the makers for further development. We have now received another pair of this type of horn, which we presume is a modified form of, and improvement on, the earlier pair. These also are exactly like our standard type on the outside, but much simpler inside. Bench tests have been carried out on them and the following observations made. (1) Each horn, separately connected to battery through relay. (Loud note). Current taken. Volts on horn terminals Treble horn. 5.0 amperes. 11.55 Alto horn. 4.4 amperes. 11.60. | ||